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• casement
  casement

  noun

  a window sash opening on hinges that are generally attached to the upright side of its frame.
• Casement
  Casement

  noun

  (Sir) Roger (David), 1864–1916, Irish patriot: hanged by the British for treason.

casement

¹ American  

[keys-muhnt] / ˈkeɪs mənt /

noun

1. a window sash opening on hinges that are generally attached to the upright side of its frame.

2. Also called casement window.  a window with such a sash or sashes.

3. a casing or covering.

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Casement ² American  

[keys-muhnt] / ˈkeɪs mənt /

noun

1. (Sir) Roger (David), 1864–1916, Irish patriot: hanged by the British for treason.

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casement ¹ British  

/ ˈkeɪsmənt /

noun

1. a window frame that is hinged on one side

2. a window containing frames hinged at the side or at the top or bottom

3. a poetic word for window

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Casement ² British  

/ ˈkeɪsmənt /

noun

1. Sir Roger ( David ). 1864–1916, British diplomat and Irish nationalist: hanged by the British for treason in attempting to gain German support for Irish independence

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Other Word Forms

• casemented
  adjective

Etymology

Origin of casement

1375–1425; late Middle English. See case ², -ment

Explanation

A casement is a type of window that swings open on a hinge, like a door. Open the casements in the kitchen and let the breeze come in! Before the invention of the sash window, which slides up and down, casements were very common. Today, you're more likely to see casement windows in European homes than in the U.S. Extremely old houses, especially those built before the 17th century, commonly have casement windows with leaded glass panes. Experts guess that the word casement comes from the Old French enchassement, "window frame."

Example Sentences

See Examples For:

casement Casement

It also comes complete with two staircases, window seats, and casement windows.

From MarketWatch ● Jun. 26, 2026

The casement windows on the second floor were probably added in the 1920s — casement windows became popular then — and those very large ground-floor picture windows came later.

From New York Times ● Nov. 21, 2022

"When it struck the quarters, the whole room shook and then the joy of somebody coming in, opening the casement, putting the rod in and winding it up," she said.

From BBC ● Feb. 20, 2022

The bedrooms all have tall casement windows that open out for the breeze and transom windows for extra natural light.

From Washington Post ● Dec. 1, 2021

I used electrical tape to attach cardboard fins to the casement and then borrowed Mom’s fingernail polish to paint a name on the side.

From "October Sky" by Homer Hickam

In order to be ready for the tournament, Casement Park needed to be rebuilt by the summer of 2027.

From BBC ● Jul. 3, 2026

Antoin Duffy, with an address at Braade, Kincasslagh, County Donegal, was extradited from Scotland and arrested at Casement Aerodrome in Baldonnell in Dublin.

From BBC ● Mar. 30, 2026

Depression is one of the leading causes of disability among people ages 16 to 24, Casement said.

From Science Daily ● Jan. 7, 2026

"Instead of being a morning lark you're going to become more of a night owl," Casement explained.

From Science Daily ● Jan. 7, 2026

In the lower reaches of the river above Stanley Pool Casement found no gross ill-usage.

From The Crime of the Congo by Sir Arthur Conan Doyle